Expanding tire-supporting wheel apparatus

ABSTRACT

An expanding wheel apparatus for temporarily supporting a pneumatic tire during operations such as buffing, grinding, smoothing and dressing preparatory to recapping or retreading the tire. The apparatus includes a rotatable shaft to which is keyed a scroll wheel. A jaw support is rotatably supported by the shaft, with a plurality of jaws being carried by such jaw support for radial movement relative thereto. Engaged helically extending teeth are carried by the jaws and the scroll wheel. When the jaw support is locked in place, the rotation of the scroll wheel will extend or retract the jaws. The jaws support a radially expandable band assembly that receives the tire when such assembly is in a contracted position. The wheel assembly is radially expanded when the jaws undergo radial movement relative to the scroll wheel.

United. States Patent Primary ExaminerDonald R. Schran Attomey-Fulwider,Patton, Rieber, Lee and Utecht ABSTRACT: An expanding wheel apparatusfor temporarily supporting a pneumatic tire during operations such asbuft'mg, grinding, smoothing and dressing preparatory to recapping orretreading the tire. The apparatus includes a rotatable shaft to whichis keyed a scroll wheel. A jaw support is rotatably supported by theshaft, with a plurality of jaws being carried by such jaw support forradial movement relative thereto. Engaged helically extending teeth arecarried by the jaws and the scroll wheel. When the jaw support is lockedin place, the rotation of the scroll wheel will extend or retract thejaws. The jaws support a radially expandable band assembly that receivesthe tire when such assembly is in a contracted position. The wheelassembly is radially expanded when the jaws undergo radial movementrelative to the scroll wheel.

llll llll EXPANDING TIRE-SUPPORTING WHEEL APPARATUS BACKGROUND OF THEINVENTION 1. Field of the Invention The present invention relates totire mounting and inflating apparatus and more particularly to a powerexpanded wheel that temporarily supports a tire for rotation.

2. Description of the Prior Art Prior art is represented by U.S. Pat.Nos. 2,960,130; and 3,291,171.

SUMMARY OF THE INVENTION The tire supporting apparatus of the presentinvention is characterized by a frame which rotatably supports a shaft.A jaw support is rotatably supported by this shaft, with such jawsupport in turn carrying a plurality of jaws for radial movement, thejaws being fonned with helically extending teeth. A radially expandableband assembly is supported by the jaws, such wheel assembly receiving atire when the wheel assembly is disposed in a contracted position.Ascroll wheel is keyed to the shaft and is formed with helicallyextending teeth that are engaged with the teeth of the jaws. A couplingis interposed between the jaw support and the frame. Control means areprovided for activating the coupling to temporarily lock the jaw supportand allow relative rotation of the scroll wheel whereby the jaws undergoradial outward movement to thereby expand the band assembly and the tiredisposed thereon. The scroll wheel and jaw arrangement affords truerunning over an extended service life because of the positiveinterconnection between the wheel and the jaws.

The tire supporting apparatus of the presentinvention also utilizes aresilient shroud which encloses the radially moveable elements of theassembly. The interior of the shroud is pressurized withsuperatmospheric air so as to preclude the entry of rubber dust into themechanism of the wheel assembly. In this manner, fouling of the movingparts is prevented.

The tire supporting apparatus of the present invention includes atire-receiving band assembly which may be readily changed to accommodatetires of varying sizes.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view, whichhasbeen partially broken away in central vertical section, of a preferredform of tire mounting apparatus embodying the present invention;

FIG. 2 is a fragmentary view similar to FIG. 1 showing the parts of thetire mounting apparatus in an expanded position;

FIG. 3 is a fragmentary front elevational view of said tire mountingapparatus;

FIG. 4 is a vertical sectional view taken on line 4-4 of FIG. 2;

FIG. 5 is a fragmentary central vertical sectional view taken inenlarged scale on line 5-5 of FIG. 4;

FIG. 6 is a vertical sectional view taken on line 6-6 of FIG.

FIG. 7 is a vertical sectional view taken in enlarged scale along line7-7 of FIG. 2;

FIG. 8 is a fragmentary view taken from the point designated 8 in FIG.7;

FIG. 9 is a vertical sectional view taken in enlarged scale on line 9-9of FIG. 7;

FIG. I0 is a vertical sectional view taken in further enlarged scalealong line 10-10 of FIG. 9;

FIG. 11 is a fragmentary vertical sectional view showing how the bandassembly may be replaced;

FIGS. l2, l3 and 14 are diagrammetrical views showing'the operation ofthe scroll wheel and jaws of said apparatus; and

FIG. 15 is a broken front view showing a jaw-stop utilized in saidapparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, apreferred form of tire supporting apparatus embodying the presentinvention includes generally a frame F, a horizontally extending shaft20 rotatably supported on the frame, a jaw support generally designated22 which is rotatably supported by the shaft 20, a plurality of likejaws generally designated 24 carried-by the jaw support 22 for radialmovement'relative thereto, a radially expandable band assembly Bsupported by the jaws 24 with such wheel assembly receiving a tire Twhen the band assembly is disposed in a contracted position, a scrollwheel generally designated 26 keyed to the shaft 20, a yieldablecoupling such as a brake generally designated 28, interposed between theshaft 20 and jaw support 22, and control means to be describedhereinafter which actuate the brake 28 to temporarily lock the jawsupport while allowing rotation of the scroll wheel. The jaws 24 and thescroll wheel 26 are formed with complimentary helically extending teethwhereby the jaws will undergo radial outward movement and expand thebead assembly B and the tire T disposed thereon when the jaw support istemporarily locked and there is relative rotation of the scroll wheel,the parts of the apparatus moving from their position shown in FIG. 1 totheir position shown in FIG. 2'as the wheel assembly A undergoes suchradial expansion. A resilient shroud 30 encloses the scroll wheel 26 andjaws 24.

More particularly, the frame F includes a horizontal base 40 uponwhichis secured an upright housing 42. The upper portion of the housing 42supports the shaft 20 by suitable bearing means. The shaft 20 is rotatedby an electric motor 44 through a gear box 46 in a conventional manner.The shaft 20 is provided with an axially extending air passage 48 (FIG.5), the rear end of which is connected to a source of pressurized air bymeans of a hose 48 through a conventional fitting 50. Such fittingpermits relative rotation between the shaft and the hose 48 Referringnow additionally to FIG. 5, the jaw guide 22 is of generally annularconfiguration and includes a collar portion 50 which is bored to snuglyreceive the shaft 20. A plurality of radially extending air passages 52are formed in the jaw support through collar portion 50 to connect withradial extensions 54 of the axial shaft passage 48. Seal rings 56 arecarried by the collar portion 50 on either side of the passages 52. Aforward extension 58 of at least one of the axial passages 52 isprovided. Front and rear bearings 60 and 62'are interposed between thejaw support 22 and the shaft 20. The rear portion of the jaw supportisformed with a rearwardly extending drum element 64 that encircles thebrake 28. The jaws 24 are radially slidably supported withincomplimentary radially extending slots 68 formed in the forward portionof the jaw support 22; The jaws 24 are of like construction and areformed at their front portion with a plurality of generally helicallyextending teeth 72. The radially outer portion of each jaw 24 is rigidlysecured to an end piece 74. The end pieces 74 are of like construction.Jaw stops 76 are provided on the jaw support 22 to limit radial outwardmovement of the jaws 24, as shown particularly in FIG. 15'.

The shroud 30 is fonned of a suitable resilient material such as asynthetic rubber. The rear end of the shroud is affixed to theintermediate portion of the jaw support 22 by a clamp 80. Theintermediate portion of the shroud is retained upon the outwardly-facingsurfaces of the jaw end pieces 74 by means of a plurality of cap strips82, one cap strip being provided for each of the end pieces. The capstrips 82'are secured to the end pieces 74 by cap screws 84. The frontend of the shroud 30 is sandwiched between an end plate 86 and aretainer plate 88. The end plate 86 and retainer plate 88 are coaxiallyrotatably supported upon the front end of the shaft 20 by means of ashoulder bolt 90, the shoulder portion 92 thereof abutting the front endof the shaft 20. It should be noted that the shoulder portion 92 of boltis of sufficient length to permit axial 'slidial movement of the plates86 and 88 therealong. It v should be further noted that theplate 86 isformed with apertures 96 and that the central bore 97 of end plate;88-isgreater than the diameter of bolt shoulder 92.

The scroll wheel26 includes a main body 100 and ascroll I02securedwithin an annular groove 102 forrned'in the rear peripheral portion ofthe body 100 by a plurality of screws 104. The rear portion of thescroll 102 is formed with helically extending threads 106 that arecomplimentally engaged with the threads 72 formed in the jaws 24. A key107 is interposed in complimentary axial slots formed in the main body100 and the front portion of the shaft 20. A nut 108 and a washer 110interposed therebetween secure the body 100 of the scroll wheel in placeupon the front end of shaft 20.

The brake is of convention construction and includes a resilient bladder120 that encircles a dish-shaped retainer 122 affixed to a bearingretainer 124 disposed on the front of the frame housing 42. The interiorof the bladder 120 is connected with a source of superatmospheric air bymeans of a fitting 126 and tubing 128. The radially outer surface of thebladder 120 supports brake lining material 130. In the operation of thebrake 28., pressurized air is admitted to the interior of the bladder120 so as to effect radially outward expansion thereof with suchexpansion moving the brake lining material 130 into yielding frictionalengagement with the interior of the drum 64 ofjaw support 22.

As shown particularly in FIGS. 2 and 3 through 8, the expanding bandassembly B includes a plurality of segment members generally designated150 of like construction, arcuate connector plates 151, and an airtightresilient band 152 which encircles the segments and connector plates andretains them together as a single unit. As indicated particularly inFIGS. 3 and 4, each segment 150 is generally T-shaped when viewed fromthe front of the apparatus and includes a radially extending leg 154which is integral at its radially outer end with a head 155. Theradially outer surface of each head I55 is of annular configuration,with such radially outer surfaces collectively defining a circle. Theconnector plates 151 are of like construction and include an arcuateelement 156 that bridges two adjoining segment heads S and a radiallyinwardly extending pin 157 disposed in a slot 158 of one of the segmentheads as shown in FIGS. 7 and 8. The radially inner ends of the legs 154are formed with axially extending grooves I60 which are slidablyreceived by the radially outer ends of the cap strips 82 of the jaws 24,a segment 150 being provided for each of the jaws 24. If desired, theradially inner surfaces of the legs 154 may be inclined at an angle tofacilitate sliding the legs I50 rearwardly onto and forwardly off thecap strips 82 in a manner to be described hereinafter. It should beparticularly noted that the band assembly B is a unitary self-supportingunit which facilitates manual handling thereof.

Referring to FIGS. 9 and 10, it should be noted that preferably the band152 is formed of a resilient material such as synthetic rubber intowhich is molded transversely-extending cross strands of cordage 163providing minimum transverse stretching while permitting freecircumferential stretching of the band. This arrangement precludeslateral stretch and consequent folding or buckling of the band by thetire beads during expansion of the band assembly B.

Referring again to FIG. 1, the control system for the apparatus of thepresent invention includes a motor control box generally designated 180secured to the upper rear portion of the frame housing 42. The switchbox 180 includes a forward switch 182, areverse" switch 184, and a stop"switch 186. To effect forward rotation of the shaft 20, switch 182 isdepressed. If switch 186 is depressed the shaft will stop and thereafterswitch 184 may be depressed so as to effect reverse rotation of theshaft 20.

The upper rear portion of the frame housing 42 carries a low-pressurepush button 188 for operating the brake 28. When this push button isdepressed, air under comparatively low superatmospheric pressure will bedirected into the confines of the bladder 120 so as to expand the brakeliner materi al 130 into yielding engagement with the interior of thejaw support drum 64. A high-pressure brake push button 190 is mounted atthe lower portion of the frame housing 42. When this button isdepressed, air under higher pressure than that admitted by depressingpush button 188 is directed into the interior of the bladder 120. A tireinflate-dcflate lever I92 is mounted on the upper front portion of theframe housing 42. This handle 192 is suitably connected to conventionalvalving so as to direct superatmospheric air through the passages 48 and54 of shaft 20 and passages 52 of jaw support 22. This pressurized airwill then be conducted to one or more of the segments by means offlexible tubing 193. As indicated in FIGS. 7 and 9, a segment 150a isformed with an air passage 194. The outer end of passage 194 receives afitting 195 connected with flexible tubing 193. The opposite end of thispassage I94 terminates in a second fitting 196 that extends radiallyoutwardly through band 152 so as to conduct air into the interior oftire T. A pressure-relief valve (not shown) may also be provided in oneor more of the segments to discharge air from between band 152 and theinterior of tire T.

In the operation of the aforedescribed apparatus, with the parts of theapparatus disposed in their position of FIG. 1, a tire T is slipped ontothe band assembly B. Such band assembly being in a contracted position.Thereafter the operator moves the air control lever 192 into its tireinflating position. Pressurized air is then directed into the confinesof the tire T. The operator then depresses the forward motor controlswitch 182 so as to effect forward rotation of the shaft 20. Since thebrake 28 is actuated, the jaw support 22 will be yieldingly restrainedagainst rotation with the shaft 20 and, accordingly, the jaws 24 andtheir associated parts will undergo radially outward movement relativeto the scroll wheel 26. This movement is shown in FIGS. 12, 13 and 14wherein it will be noted that because of the interengagement of the jawthreads 72 with the scroll wheel threads 106, the jaws 24 will be urgedradially outwardly relative to the scroll wheel 26.

Radial outward movement of the jaws 24 and their associated parts willcontinue until these parts assume their position indicated in FIG. 2. Atthis time, the beads of the tire T will be maintained in sealingengagement with the band 152. At this point, brake control switch 188 isreleased and the frictional resistance between the threads 72 and 106 ofthe jaws 24 and the scroll wheel 26 will preclude reverse radiallyinward movement of the jaws relative to the scroll wheel. The tire T isnow undergoing forward rotation and the desired tire treating operation,such as bufi'ing may take place. At the conclusion of such operation,the air control lever 192 is moved to its deflate" position. This servesto vent the interior of the tire T with the atmosphere by means ofsuitable conventional valving. Forward rotation of the shaft 20 is thenstopped. The operator then pushes the reverse" switch 184 so as toeffect reverse rotation of the shaft 20, and at approximately the sametime the operator again pushes the low-pressure brake push button 188.This should cause the jaws 24 to undergo radially inward movementrelative to the scroll wheel 26 Occasionally, however, it is necessaryto apply higher brake pressure to overcome the frictional resistancebetween the jaws 24 and the scroll wheel 26 and in such event, theoperator depresses the high-pressure push button 190.

It should be particularly noted that during the tire buffing operationor other such operation wherein rubber dust is produced, such dust isprevented from fouling the jaws 24 and scroll wheel 26 by means of theshroud 30, pressurized air entering this space through shaft passages 48and 54 and jaw support passages 52 and 58. As shown clearly in FIG. 5,it should be noted that even should the shroud 30 be punctured or shouldanother type of air leak occur, the constant introduction of pressurizedair within the space encompassed by the shroud 30 will insure that noforeign matter can enter such space, When the bead assembly B isretracted, air will escape from within the shroud through apertures 96formed in plate 88 and the space between the bore 97 of end plate 86 andthe shoulder 92 of bolt 90.

Referring now to FIG. 13, it should be particularly noted that it is anadvantage of the tire supporting apparatus of the present invention thatthe bead wheel assembly B may be readily changed to accommodate tires ofvarying sizes. Thus, assuming that a tire of smaller diameter than couldbe accommodated by the bead wheel assembly B shown in the drawings is tobe buffed a second bead assembly (not shown) may be provided havingsegments 150 of shorter length than those shown in FIGS. 1 through 7 isemployed. Referring to FIG. ll, to remove the first bead wheel assemblyB, a stop ring R is utilized. This stop ring R is arranged in itsinoperative position of FIGS. 1 and 2 during normal operation of theapparatus. As indicated in FIG. 11, stop ring R includes a lip 200 whichis received within a complimentary annular groove 202 formed in the rearradially inner portion of each of the segments 150. The diameter of thestop ring is adequate to maintain the radially inner surface of the beadassembly B outwardly from the cap strips 82 when the jaws are disposedin their radially inner contracted position. To remove the bead assemblyB from the jaw cap strips 82, the lip 200 of the stop ring R is insertedwithin the grooves 202 as the head assembly B is being retracted. Whenthe jaws 24 have been completely retracted, the stop ring R will supportthe bead assembly B in a circular configuration free of the jaw capstrips 82. As indicated in FIG. 11. the bead assembly B may then bereadily moved axially forwardly off of the cap strips 82. A second beadassembly B of a different outside diameter may then be slid over the jawcap strips 82. As the second bead assembly B undergoes ex pansion thestop ring R may be removed therefrom for'subsequent use dtiring the nextbead wheel assembly change. The stop ring R therefor considerablyfacilitates the replacement of bead wheel assemblies since it eliminatesthe radially inwardly directed bind which is created by the resilientseal ring 152, such ring having a smaller relaxed diameter than thediameter of the circle defined by the jaw cap strips 82 when the jawsare completely retracted.

While there has been shown and described hereinbefore what is presentlyconsidered to be a preferred embodiment of the present invention, itwill be apparent that various modifications and changes may be madethereto without departing from the spirit of the present invention.

We claim:

1. Tire supporting apparatus, comprising;

a frame;

a shaft rotatably supported on said frame;

ajaw support rotatably supported by said shaft;

a plurality of jaws carried by said jaw supportfor radial movementrelative thereto, said jaws being formed with helically extending teeth;

a radially expandable band assembly supported by said jaws, said bandassembly receiving a tire when said band as sembly is disposed in acontracted position;

a scroll wheel keyed to said shaft and formed with helically extendingteeth engaged with the teeth of said jaws;

coupling means interposed between said jaw support and said frame; andcontrol means for actuating said coupling means to thereby temporarilyrestrain said jaw support against rotation relative to saidframe wherebysaid jaws undergo 5 radial outward movement and expand said wheelassembly and the tire disposed thereon.

2. Tire supporting apparatus as set forth in claim 1 wherein saidcoupling means is a yieldably applicable brake.

3. Tire supporting apparatus as set forth in claim 1 which furtherincludes a pneumatic system for inflating said tire.

4. Tire supporting apparatus as set forth in claim 3 wherein a resilientshroud encloses said jaws and said scroll wheel and said pneumaticsystem supplies air under superatmospheric pressure to the interior ofsaid shroud when said wheel assembly is expanded.

5. Tire supporting apparatus as set forth in claim 1 wherein said bandassembly includes a plurality of segments having radially inner portionsreceived by said jaws and radially outer portions which are encircled byan airtight resilient band that retains said segments together as asingle unit, with the relaxed diameter of said bands being less than theexpanded diameter of said wheel assembly.

6. Tire supporting apparatus as set forth in claim 5 wherein theradially inner portions of said segments are removably supported by saidaws, and said apparatus also includes a stop ring selectively engageablewith said segments to retain said segments together defining a'circlehaving an inner diameter greater than the outer diameter of the circledefined by said jaws when said jaws are arranged to support said bandas- 30 sembly in said contracted position;

7. Tire supporting apparatus, comprising:

a frame;

a shaft rotatably supported on said frame;

a radially expandable band assembly carried by said shaft for radialmovement relative thereto, said band assembly receiving the beads of atire; power-operated radially movable elements interposed between saidshaft and said band assembly to effect radial expansion and contractionof said band assembly and a tire disposed thereon;

a resilient shroud enclosing said radially movable elements to restrainforeign matter from contact therewith; first air passage means extendingthrough said band assembly to the interior of said tire; second airpassage means extending through said shroud;

and a pneumatic system for introducing air under superatmosphericpressure through. said first and second air passage means.

1. Tire supporting apparatus, comprising: a frame; a shaft rotatablysupported on said frame; a jaw support rotatably supported by saidshaft; a plurality of jaws carried by said jaw support for radialmovement relative thereto, said jaws being formed with helicallyextending teeth; a radially expandable band assembly supported by saidjaws, said band assembly receiving a tire when said band assembly isdisposed in a contracted position; a scroll wheel keyed to said shaftand formed with helically extending teeth engaged with the teeth of saidjaws; coupling means interposed between said jaw support and said frame;and control means for actuating said coupling means to therebytemporarily restrain said jaw support against rotation relative to saidframe whereby said jaws undergo radial outward movement and expand saidwheel assembly and the tire disposed thereon.
 2. Tire supportingapparatus as set forth in claim 1 wherein said coupling means is ayieldably applicable brake.
 3. Tire supporting apparatus as set forth inclaim 1 which further includes a pneumatic system for inflating saidtire.
 4. Tire supporting apparatus as set forth in claim 3 wherein aresilient shroud encloses said jaws and said scroll wheel and saidpneumatic system supplies air under superatmospheric pressure to theinterior of said shroud when said wheel assembly is expanded.
 5. Tiresupporting apparatus as set forth in claim 1 wherein said band assemblyincludes a plurality of segments having radially inner portions receivedby said jaws and radially outer portions which are encircled by anairtight resilient band that retains said segments together as a singleunit, with the relaxed diameter of said bands being less than theexpanded diameter of said wheel assembly.
 6. Tire supporting apparatusas set forth in claim 5 wherein the radially inner portions of saidsegments are removably supported by said jaws, and said apparatus alsoincludes a stop ring selectively engageable with said segments to retainsaid segments together defining a circle having an inner diametergreater than the outer diameter of the circle defined by said jaws whensaid jaws are arranged to support said band assembly in said contractedposition.
 7. Tire supporting apparatus, comprising: a frame; a shaftrotatably supported on said frame; a radially expandable band assemblycarried by said shaft for radial movement relative thereto, said bandassembly receiving the beads of a tire; power-operated radially movableelements interposed between said shaft and said band assembly to effectradial expansion and contraction of said band assembly and a tiredisposed thereon; a resilient shroud enclosing said radially movableelements to restrain foreign matter from contact therewith; first airpassage means extending through said band assembly to the interior ofsaid tire; second air passage means extending through said shroud; and apneumatic system for introducing air under superatmospheric pressurethrough said first and second air passage means.